feat: consensus key rotation of validator

proto/cosmos/staking/v1beta1/staking.proto

@@ -320,6 +320,10 @@ message Params {
     (amino.dont_omitempty) = true,
     (cosmos_proto.scalar)  = "cosmos.Dec"
   ];
+  // max_cons_pubkey_rotations is maximum number of consensus pubkey rotations
+  uint64 max_cons_pubkey_rotations = 7;
+  // cons_pubkey_rotation_fee is fee to be spent when rotating validator's consensus pubkey
+  cosmos.base.v1beta1.Coin cons_pubkey_rotation_fee = 8 [(gogoproto.nullable) = false];
 }
 
 // DelegationResponse is equivalent to Delegation except that it contains a
@@ -392,3 +396,24 @@ enum Infraction {
 message ValidatorUpdates {
   repeated tendermint.abci.ValidatorUpdate updates = 1 [(gogoproto.nullable) = false, (amino.dont_omitempty) = true];
 }
+
+// ConsPubKeyRotationHistory contains a validator's consensus public key rotation history.
+message ConsPubKeyRotationHistory {
+  option (gogoproto.equal)            = false;
+  option (gogoproto.goproto_getters)  = false;
+
+  // operator_address defines the address of the validator's operator; bech encoded in JSON.
+  string operator_address = 1 [(gogoproto.moretags) = "yaml:\"operator_address\""];
+  // old_cons_pubkey is the old consensus public key of the validator, as a Protobuf Any.
+  google.protobuf.Any old_cons_pubkey = 2 [
+    (cosmos_proto.accepts_interface) = "cosmos.crypto.PubKey",
+    (gogoproto.moretags)             = "yaml:\"old_consensus_pubkey\""
+  ];
+  // new_cons_pubkey is the new consensus public key of the validator, as a Protobuf Any.
+  google.protobuf.Any new_cons_pubkey = 3 [
+    (cosmos_proto.accepts_interface) = "cosmos.crypto.PubKey",
+    (gogoproto.moretags)             = "yaml:\"new_consensus_pubkey\""
+  ];
+  // height defines the block height at which the rotation event occured.
+  uint64 height = 4;
+}

proto/cosmos/staking/v1beta1/tx.proto

@@ -45,6 +45,11 @@ service Msg {
   // parameters.
   // Since: cosmos-sdk 0.47
   rpc UpdateParams(MsgUpdateParams) returns (MsgUpdateParamsResponse);
+
+  // RotateConsPubKey defines an operation for rotating the consensus keys
+  // of a validator.
+  // Since: cosmos-sdk 0.48
+  rpc RotateConsPubKey(MsgRotateConsPubKey) returns (MsgRotateConsPubKeyResponse);
 }
 
 // MsgCreateValidator defines a SDK message for creating a new validator.
@@ -204,3 +209,23 @@ message MsgUpdateParams {
 //
 // Since: cosmos-sdk 0.47
 message MsgUpdateParamsResponse {};
+
+// MsgRotateConsPubKey is the Msg/RotateConsPubKey request type.
+//
+// Since: cosmos-sdk 0.48
+message MsgRotateConsPubKey {
+  option (cosmos.msg.v1.signer) = "validator_address";
+  option (amino.name)           = "cosmos-sdk/MsgRotateConsPubKey";
+
+  option (gogoproto.goproto_getters) = false;
+  option (gogoproto.equal)           = false;
+
+  string validator_address        = 2 [(cosmos_proto.scalar) = "cosmos.AddressString"];
+  google.protobuf.Any new_pubkey = 3 [(cosmos_proto.accepts_interface) = "cosmos.crypto.PubKey"];
+}
+
+// MsgRotateConsPubKeyResponse defines the response structure for executing a 
+// MsgRotateConsPubKey message.
+//
+// Since: cosmos-sdk 0.48
+message MsgRotateConsPubKeyResponse {}